The present application relates generally to registering multiple datasets with each other. In an exemplary embodiment, the present invention relates to registering differing ophthalmic datasets from different measurements (such as a wavefront measurement and a corneal topography map) of an eye.
Known laser eye procedures generally employ an ultraviolet or infrared laser to remove a microscopic layer of stromal tissue from the cornea of the eye to alter the refractive characteristics of the eye. The laser removes a selected shape of the corneal tissue, often to correct refractive errors of the eye. Ultraviolet laser ablation results in photo-decomposition of the corneal tissue, but generally does not cause significant thermal damage to adjacent and underlying tissues of the eye. The irradiated molecules are broken into smaller volatile fragments photochemically, directly breaking the intermolecular bonds.
Laser ablation procedures can remove the targeted stroma of the cornea to change the cornea's contour for varying purposes, such as for correcting myopia, hyperopia, astigmatism, and the like. Control over the distribution of ablation energy across the cornea may be provided by a variety of systems and methods, including the use of ablatable masks, fixed and moveable apertures, controlled scanning systems, eye movement tracking mechanisms, and the like. In known systems, the laser beam often comprises a series of discrete pulses of laser light energy, with the total shape and amount of tissue removed being determined by the shape, size, location, and/or number of a pattern of laser energy pulses impinging on the cornea. A variety of algorithms may be used to calculate the pattern of laser pulses used to reshape the cornea so as to correct a refractive error of the eye. Known systems make use of a variety of forms of lasers and/or laser energy to effect the correction, including infrared lasers, ultraviolet lasers, femtosecond lasers, wavelength multiplied solid-state lasers, and the like. Alternative vision correction techniques make use of radial incisions in the cornea, intraocular lenses, removable corneal support structures, thermal shaping, and the like.
Known corneal correction treatment methods have generally been successful in correcting standard vision errors, such as myopia, hyperopia, astigmatism, and the like. However, as with all successes, still further improvements would be desirable. Toward that end, wavefront measurement instruments are now available to measure the refractive characteristics of a particular patient's eye.
One promising wavefront measurement system is the iDESIGN ADVANCED WAVESCAN STUDIO System, which includes a Hartmann-Shack wavefront sensor assembly that may quantify higher-order aberrations throughout the entire optical system, including first and second-order sphero-cylindrical errors and third through sixth-order aberrations caused by coma and spherical aberrations. With advanced algorithms for measuring and applying the wavefront correction (e.g. Fourier or zonal), even higher spatial frequency structures can be corrected, providing that adequate registration can be maintained between the intended correction and its application in a practical system. The wavefront measurement of the eye creates a high order aberration map that permits assessment of aberrations throughout the optical pathway of the eye, e.g., both internal aberrations and aberrations on the corneal surface. Thereafter, the wavefront aberration information may be saved and thereafter input into a computer system to compute a custom ablation pattern to correct the aberrations in the patient's eye. A variety of alternative wavefront or other aberration measurement systems may also be available
Customized refractive corrections of the eye may take a variety of different forms. For example, lenses may be implanted into the eye, with the lenses being customized to correct refractive errors of a particular patient. By customizing an ablation pattern or other refractive prescription based on wavefront measurements, it may be possible to correct minor refractive errors so as to reliably and repeatably provide visual acuities better than 20/20. Alternatively, it may be desirable to correct aberrations of the eye that reduce visual acuity, even where the corrected acuity remains less than 20/20.
While wavefront measurement systems have been highly successful, improvements are still possible. For example, in some instances it may be desirable to concurrently diagnose the refractive errors of the eye using two or more different optical measurements so as to provide a better diagnosis (and treatment) of the refractive errors in the optical tissues of the eye. For example, the iDESIGN ADVANCED WAVESCAN STUDIO System includes both a wavefront aberrometer and corneal topographer. In order to fully take advantage of two different data sources for corneal treatment planning, however, it will generally be desirable to combine the data from the two optical measurement instruments.
Consequently, what is needed are methods, systems and software for registering datasets from separate optical measurement devices.
Multi-modal diagnostic instruments are being developed that acquire data from different measurements of the eye. For example, a multi-modal diagnostic instrument may include, for example, wavefront aberrometry and corneal topography (CT), optical coherence topography (OCT) and wavefront (WF), optical coherence topography and topography, pachymetry and wavefront, and so forth. The different measurements taken by these multi-modal diagnostic instruments may be more useful if are be registered together. Often it is difficult to acquire the images at exactly the same time, which requires synchronized cameras. Accordingly, it would be useful to provide systems and methods that allow image data to be registered that was taken by different devices, or the same device, at different times.